Process for the production of pure guar meal

ABSTRACT

A method for producing pure guar meal and the use of hydroxy propyl trimethyl ammonium chloride—guar meal obtained according to the method in clear aqueous cosmetic formulations which are intended to be applied on hair and/or skin and which can be washed out or rinsed off as conditioning agents or depositing agents to dilute cosmetic formulations.

[0001] The invention relates to a process for the production of guarmeal, which, if it is dissolved in water, yields a transparent solutionof varying viscosity, i.e. low to very high, whereby the processsupplies good yields of the pure meal in spite of extensivepurification. Transparent, high-viscosity solutions of pure guar mealare primarily of great significance in the foodstuffs industry.

[0002] Guar meal is used as a thickening agent in the textile andexplosives industries, as a binding agent in the paper industry, as aflocculent in ore production, as an aid in the extraction of natural gasand petroleum, in the pharmaceutical and cosmetic fields and as athickening agent, emulsifier and co-stabilizer in foodstuffs.

[0003] In pharmaceuticals, low viscosity guar meal is used forspray-embedding vitamins, for example, in order to increase theirstorage stability. Beyond that, the use of guar meal in spraysguarantees a nearly monomolecular distribution of the substance and aresulting even re-absorption, which is desirable in the case of asthmamedications and various anti-allergics. Due to the extraordinarily lowprotein content of the pure guar meal, there is no danger of developingan allergic reaction to a medication containing this substance.Additional applications in this field are the formulation of retardtablets and use as an agent for reducing cholesterol levels. In thefield of medicines, very viscous guar meal is also used as a stabilizerin contrast media.

[0004] Guar meal has also proven itself as, among other things, an idealdietetic agent, since its components, the so-called galactomannans, arenot affected by enzymes of the human stomach and small intestines. Thisis to be expected, since in the re-absorbing part of the human digestionsystem neither β-mannanase nor β-mannosidase nor α-galactosidase ispresent, which would be necessary to break down these components. Sincethe components of the guar meal are not involved in the humanmetabolism, guar meal is in no way to be viewed as a carrier or supplierof calories. Since guar meal is composed of completely neutralpolysaccharides, i.e. galactomannans, which have neither uronic acid norother ionic groups, they represent completely harmless material from aphysiological standpoint.

[0005] A further advantage with regard to its use as a food supplementis its complete taste neutrality. It is used in calorie-reducing orfat-reducing foods or drinks, which are frequently felt by the consumerto be “thin”. The addition of pure guar meal to these products lends a“creamy” consistency to them. Guar meal is used in the production offruit juices in order to re-suspend the fruit pulp evenly, in puddingsand cremes it is used as a thickener, and in ice creams, milkshakes,mousse and similar products it is used as a stabilizer.

[0006] With standard guar meal preparations, only a slight molecularinteraction was ever recorded with the biopolymer xanthane. Although inmixing these two colloids, a synergistic increase in viscosity indeedoccurred, a specific gel formation as in the case of carubin, however,did not occur with carob meal and xanthane. If one heats up mixtures ina ratio of 1:1 of the guar meal obtained according to the invention andxanthane and lets them cool at 4° C. (refrigerator temperature), a softgel forms. An advantage of this combination of guar meal and xanthaneconsists in that the gel from these two components melts at bodytemperature and is therefore exceptionally well-suited for theproduction of jelly-type foods, as a carrier substance in theadministration of medications and the like. Guar meal and xanthane arealso used together as co-stabilizers in the production of saladdressings, since this combination, in contrast to guar meal used byitself, is acid-resistant.

[0007] Guar meal is obtained from the endosperm of the guar seed(cyamopsis tetragonobolus). Guar meal consists primarily ofgalactomannans, i.e. polysaccharides the main chain of which is linkedin the 1->4 direction by β-glycosidic bonds and is composed of mannosethat is partially linked to galactose through primary OH groups. Theratio of non-substituted mannose to mannose substituted with galactoseis approximately 2:1, wherein the substituted units are not strictlyalternating, but instead are arranged in groups of two or three in thepolygalactomannan molecules. The guar-galactomannans form highly viscoussolutions even in low concentrations with water. 1 percent-by-weight)solutions of commercially standard guar meal in water yield viscositiesof approximately 3,000 to 6,000 mPa.s.

[0008] Guar-galactomannans, because of chemical and physical-chemicaldifferences, have been subdivided into galactomannans soluble in coldwater, galactomannans soluble in hot water and insoluble galactomannans.

[0009] To obtain and purify the guar meal, the guar-seed is mechanicallytreated, whereby about 35 parts of unpurified guar endosperm halves andabout 60 parts of guar meal are obtained. The guar meal consistsessentially of the germ of the seed, the scraped-off seed hulls andsmall endosperm parts. The endosperm completely envelops the germ and inturn is surrounded by the seed hull. At the point of contact between theendosperm and seed hull, there is a protein rich, aleuron-like celllayer, the cells of which are tightly interlocked with the endosperm.

[0010] The unpurified endosperm halves can be further purifiedmechanically and supply splits of varying quality with regard to theirprotein content, their components that cannot be hydrolyzed by acid(A.I.R.) and the husk content. The characterization “split” typical inprofessional circles is interchangeable with the term “endospermhalves”.

[0011] Although guar meal already has broad application, it is desirableto improve its degree of purity and along with this its physical andphysiological characteristics. The purity of the guar meal is of greatimportance, in particular for its application in the foodstuffs field.Likewise desirable is a better utilization of the neutral, non-ionicmain components of the endosperm, so that these can increasingly be usedin the corresponding industrial sectors instead of cellulose derivativesthat dissolve clear in water, other polysaccharides or syntheticpolymers that dissolve clear in water.

[0012] If the products currently available on the market, consisting ofpure guar meal processed into meal, are dissolved in water for 10minutes at 25° C. or 86 to 89° C., turbid solutions are obtained. If theinsoluble material of these solutions is centrifuged with high force(>35,000×g), it turns out that 23-35% of the guar meal consists ofinsoluble material.

[0013] Microscopic studies have shown that the spun out material isprimarily composed of hull fragments, protein bodies, insolubleperipheral cells, intact, non-enclosed cells of the inner-endosperm andother seed or split impurities. A known chemical derivation of guar mealby etherization, carboxymethylization, hydroxypropylation, a combinationof these and cationization makes it possible to produce products withsignificantly improved solubility in water and with it accordinglyhigher transparency of the solutions.

[0014] One of the processes previously used to obtain pure guar mealuses chlorinated solvents, such as trichloroethylenes (see EP 0 130 946,Meyhall Chemical AG). The suspension was fractionated by simply lettingit stand or by centrifuging, wherein a protein-rich fraction (floatingfraction) developed and a protein-poor fraction (settling fraction)precipitated.

[0015] It was shown that the floating fraction of ground endosperm, suchas guar CSA 200/50 can contain up to 25% proteins and the settlingfraction, which makes up 75% of the pure meal, contains about 1.5 to1.6% protein. The settling fraction is, for example, suitable for theproduction of cationic derivatives, which, after being dissolved, yieldclear aqueous solutions. A disadvantage of this process is that finelymilled hull fragments are likewise found in the settling fraction.

[0016] A further disadvantage is the use of halogenated solvents, sincea specific weight of 1.47 to 1.48 kg/l is required. Proteins possess adensity of 1.3 kg/l and the galactomannans a density of 1.5 to 1.55kg/l, depending upon the particular moisture content. The guar mealproduced with the described process is only appropriate for technicalapplications; this guar meal cannot be used in the foodstuffs fieldsince residues of the halogenated solvent used (10 ppb were detected infractions extracted with ethanol) remain in the end product. Halogenatedsolvents are toxic and caustic to various degrees and frequently containallergenic characteristics. Also for environmental reasons, one shouldrefrain from this process.

[0017] A further process for the production of pure guar meal wasproposed as early as 1969. It consisted of an alkali treatment ofpre-soaked splits at increased temperatures, wherein 100 parts of alkaliwere absorbed by 100 parts of SPS. The large quantity of alkali, i.e.NaOH, had to be washed out. This was done with cold water in a ratio ofone part SPS (single purified splits) to 80 parts H₂O and in adehydration step with isopropanol (IPA) in which the residual NaOH ofthe purified splits was neutralized by acetic acid.

[0018] After the milling a pure guar meal of high quality was obtainedin a yield of 60-70%, based on the raw material SPS (single purifiedsplits). In 1969, this process was further developed by Stein, Hall &Co., Long Island City, N.Y., until it was ready for industrial use. Thewashing process at that time of the carboxymethylated, hydroxypropylatedor cationized guar meal (guar ether) or combinations thereof with waterwere based on this process. The purpose of this process of purifyingguar derivatives is to remove hull fragments and peripheral cell layers,as well as to remove by-products of the various etherization reactions(hydropropylation, carboxymethylation, cationization and/or combinationsthereof).

[0019] Another known process for the production of pure guar meal is thetreatment of guar splits with acid. This process supplies a product ofoutstanding quality; i.e. the resulting material supplies yields, whendissolved in water, solutions of great clarity with simultaneouslygreater viscosity. However, a disadvantage of this process consists inthe relatively expensive procedure with multiple washing andneutralization steps. Moreover, special apparatuses that make theprocess very costly are needed for an acid treatment.

[0020] In spite of the extensive purification process described above,there has been no success thus far in obtaining a non-derivative guarmeal in an economical and environmentally friendly manner that yields aclear, aqueous solution with high viscosity with simultaneously goodyields.

[0021] The disadvantages of the previous procedure for purifying andobtaining pure guar meal are:

[0022] 1. Large losses of valuable endosperm parts in the mechanicalpurification and, as a result, lower yields of pure guar meal inrelation to the original material;

[0023] 2. Hull fragments, which are still found at the various splitqualities and to a large extent disturb the functionality of themodified end products;

[0024] 3. Peripheral, protein-rich cells of the aleuron layer thatbarely swell in water and likewise negatively influence thefunctionality of the end products;

[0025] 4. Presence of other impurities of the guar seeds such as woodparticles, which must not be present;

[0026] 5. High environmental impact

[0027] It was therefore urgently desired to develop a process for theproduction of pure guar meal that remedies the above-mentioneddisadvantages and supplies a pure guar meal in good yields that, afterits dispersion in water, results in a highly viscous solution that isprimarily used in the foodstuffs industry, pharmaceutical, dyes andpaints industries and oil extraction, to name a few examples.

[0028] It is the purpose of this invention to fulfill the above-citedrequirements, i.e. to obtain good yields of pure guar meal that is pureand particularly well-suited to the foodstuffs industry by a newproduction process that yields low to highly viscous clear aqueoussolutions.

[0029] The process according to the invention for the production of pureguar meal is defined in patent claim 1 and includes the followingstages:

[0030] (a) Treatment of guar-splits with a base in the presence of smallquantities of hydrogen peroxide

[0031] (b) Partial neutralization of the alkali splits with an acid

[0032] (c) Mechanical removal of the peripheral cells

[0033] (d) If necessary, double washing with water

[0034] (e) Treatment of the splits with an aqueous alcohol solution

[0035] An initial precondition for obtaining pure guar meal is theimprovement of the starting material, the so-called splits. The splitscovered with a hull constitute up to 42.5 percent by weight of the seed.The hull-endosperm overlapping parts, which amount to 13.5% by weight ofthe seed, are essentially insoluble in water. The germ of the seedencompasses the remaining 44%. These quantity specifications show thatthe theoretical yields of splits that can be used for the inventionwithout hull and without overlapping parts amounts to 32%.

[0036] The pure guar meal obtained according to the invention is mostadvantageously produced from splits that have a protein content of 4.2%and an A.I.R. portion of 1.8%.

[0037] Such splits can be produced after an alkaline treatment using 10to 40% caustic soda, preferably 33%, at room temperatures, butpreferably at increased temperatures.

[0038] The difference of this process, novel in relation to thepreviously known ones, which likewise include an alkaline treatment ofthe starting material, consists in the addition of low concentrations ofhydrogen peroxide during the alkaline treatment. This chemical “peeling”supplies splits from which the hull cells can be removed very easily andnearly completely with mechanical means. By treating the splits with,for example, 8-10 parts of 33% caustic soda and 1.1 parts 35% hydrogenperoxide, the peripheral cells of the splits are attacked and can beremoved by mechanical abrasion. The polysaccharides of the cell layersfound under the peripheral cells are not oxidized since the amount ofthe hydrogen peroxide used is too low.

[0039] The splits purified in this way, which can optionally be washedwith water or processed further unwashed, can still be significantlyimproved for the purposes of the invention, in that phospholipids andother “non-polar” substances are washed out. This results in a greaterclarity of the product dissolved in water and is achieved by treatmentof the purified product with an aqueous alcohol solution, preferablyaqueous isopropanol (IPA), at increased temperatures. With products notwashed with water, an addition of more caustic soda before the treatmentwith isopropanol is not necessary since the product still contains about4-7% NaOH. If the product was washed, the addition of an alkalinesolution is necessary. After the isopropanol treatment, the alkalinesplits are washed with water and milled at a desired moisture content.

[0040] The degree of hydration during the milling significantlyinfluences the characteristics of the milled end product. The higher themoisture content during grinding in a technically workable mass, thegreater the quantity of polysaccharides to become dissolved, i.e. theyield of active galactomannans is that much higher. This can beexplained by the expansion of the cell volume due to the high amount ofmoisture. During the milling, the swollen cells are forced through adefined opening or crack, whereby the cell membrane can tear, assumingthat the swollen particles are significantly larger than the openings(the elasticity of the cells likewise plays an important role). In theproduction of solutions in water, the galactomannans are released fromthe cells destroyed in this way, which is not the case with cells thatare not destroyed. In these cases, the galactomannans remain inside theintact cells and do not contribute effectively to the viscosity of thesolution.

[0041] A moisture content of about 82%, preferably 72 to 75%, isacceptable in milling for practical and technical reasons. Moisturecontents lower than 72% in milling affect the quality of the guar meal.A content higher than 82% causes technical problems.

[0042] A great advantage of this invention lies in the 25% recovery ofthe abraded peripheral cell layers, i.e. in an extreme reduction of theenvironmental impact.

[0043] An additional advantage of the present invention lies in thesimplification of the process. Only a few less steps are necessary toobtain a pure product with higher solubility and viscosity.

[0044] Another advantage of this invention consists in the possibilityof producing products for solutions with viscosities, for example, aslow as 35 mPa.s and such as are measured up to 6000 to 9,000 mPa.s witha 1% concentration in water at 25° C.

[0045] Another advantage of the invention consists in producing pureguar products, the protein content of which is as low as 0.2 to 0.5%.

[0046] The greatest advantage of this invention, however, consists inthat the previous standard purification processes are essentiallysimplified and shortened, whereby the production of pure guar mealbecomes substantially more cost-effective.

[0047] Moreover, the new process is exceptionally environmentallyfriendly, since about 25% of the sifted peripheral cell layers can berecovered. The abrasion that results in the process described here canfurthermore be used in textile printing as a thickening agent. Thismeans an optimal utilization of the starting material.

[0048] A derivation of the galactomannans of the guar meal is ofsignificance for its cold water solubility. Through the derivation (e.g.carboxylmethylation, hydropropylation, cationization, etc.) one or morenon-ionic, anionic or cationic groups are added, whereby the etherizedhard-to-access galactomannans can be dissolved even at 25° C. Thederivation typically occurs in succession to the purification. The useof the derived guar meal, however, is not allowed in food application.However, derived guar meal, in particular cation-active guar meal, isused in cosmetic products such as hair conditioner, body lotions and insimilar use.

[0049] Especially included in particular in the cationic guar mealderivatives, which can be produced from a pure guar meal obtained by theprocess according to the invention, are the hydroxypropyl-trimethylammonium chloride guar meals.

[0050] These can be obtained by etherization of a pure guar meal underbasic conditions and under an inert gas atmosphere with2.3-epoxypropyl-trimethyl-ammonium chloride as a cationic etherizationagent and by subsequent purification and separation.

[0051] The etherization can preferably be performed in two main steps:

[0052] an initial step, in which the cationic etherization agent isdiffused in the guar meal under alkaline conditions and under an inertgas atmosphere at a temperature from around 20 to 55° C., preferablyaround 30 to 50° C., and then suspended in an aqueous alcohol solution,in particular a water-isopropanol-solution that contains 25 to 70% byweight of isopropanol,

[0053] and a second, actual etherization step under an inert gasatmosphere at a temperature of about 50 to 70° C., especially preferredat a temperature of about 60 to 65° C.

[0054] The first step (the diffusion) can in particular be conducted inthe presence of sodium hydroxide, whereby of 100 parts of guar meal,approximately 1 to 4 parts by weight are accounted for by sodiumhydroxide; this step can last 15 to 60 minutes.

[0055] The second step (the actual etherization) can last approximately45 to 120 minutes.

[0056] The resulting cationic product is next brought into contact withair again at the same temperature conditions in order to slightlydepolymerize the product to the desired end viscosity. The product isthen purified one or more times by washing with an aqueous alcoholicsolution, in particular water/isopropanol. After the pH has beenadjusted with an acid, e.g. acetic acid, the cationic guar meal isseparated, for example by filtration or centrifuging, and then dried.

[0057] The quantity of etherization agent that can be used is selectedso that one obtains a cationic guar meal with a degree of substitution(SG) within the range of 0.01 to 0.4. The degree of substitution (SG)can be defined as the number of substituents of2.3-epoxypropyl-trimethyl ammonium chloride that is added per hexoseunit of guar meal.

[0058] The hydroxypropyl-trimethyl ammonium chloride guar meals can havean average molecular weight of about 50,000 to 8,000,000.

[0059] The cationic guar meal obtained by the process according to theinvention, in particular the hydroxypropyl-trimethyl ammonium chlorideguar meals, can be used in particular for the production of cosmeticformulations.

[0060] The invention thus also relates to the use of ahydroxypropyl-trimethyl ammonium chloride guar meal produced byetherization of a guar meal obtained by the process according to theinvention in clear aqueous cosmetic formulations that are specified foruse on hair and/or skin and are to be washed out or rinsed off as aconditioning agent and/or as a deposition aid for additionalconditioning agents in the dilution of these cosmetic formulations.

[0061] One understands “clear aqueous cosmetic formulations” to be anycosmetic formulation that contains at least 60% by weight of water andhas a transparency of at least 92% at 600 nanometers.

[0062] These clear cosmetic formulations can in particular be present inthe form of a conditioning shampoo, a shower gel or a liquid soap.

[0063] For an advantageous embodiment of the invention, thishydroxypropyl-trimethyl ammonium chloride guar meal has a degree ofsubstitution of about 0.01 to 0.4, preferably from about 0.05 to 0.25and an average molecular weight of about 50,000 to 3×10⁶.

[0064] It can be used in a quantity that corresponds to 0.05 to 0.5%,preferably 0.1 to 0.3% of the weight of these cosmetic formulations.

[0065] Along with the hydroxypropyl-trimethyl ammonium chloride guarmeal, there can be still other conditioning agents. These can inparticular be non-volatile silicons (polyorganic siloxanes) with aviscosity from 10,000 to 106 mPa.s in the form of particles with adiameter of under 35 nanometers, preferably from about 20 to 25nanometers.

[0066] These silicons are preferably used in the form of a pre-formedaqueous dispersion, which can have a concentration from about 20 to 60%by weight, preferably from about 30 to 50% by weight. They can also beused in the cosmetic formulations in a quantity of about 0.1 to 1% byweight, preferably from about 0.5 to 1% by weight of ingredient inrelation to the weight of the cosmetic formulation.

[0067] As silicones, polydimethyl-siloxane oils, phenylated silicon oils(diphenyl-dimeticones) and aminated silicon oils (amodimeticones) can benamed.

[0068] Finally, the invention relates to clear aqueous cosmeticformulations that are specified for use on hair and/or skin and are tobe washed out or rinsed off, whereby these formulations contain (interms of weight) the following:

[0069] about 8 to 30% by weight, preferably 10 to 20% by weight, atleast of a non-ionic, anionic, amphoteric or zwitterionic tenside,expressed as active substance,

[0070] about 0.05 to 0.5% by weight, preferably about 0.1 to 0.3% byweight, of hydroxypropyl-trimethyl ammonium chloride guar mealderivative of a guar meal produced by the process according to theinvention,

[0071] in some cases about 0.1 to 1% by weight, preferably about 0.5 to1% by weight, at least of a non-volatile silicon in an aqueous emulsion,the particle size of which is less than 35 nanometers, preferably about20 to 25 nanometers, expressed as ingredient,

[0072] and at least 60% by weight of water, preferably at least 75% byweight of water.

[0073] The clear aqueous cosmetic formulations according to theinvention have a transparency of at least 92% at 600 nanometers.

[0074] Falling under the non-ionic, anionic, amphoteric or zwitterionictensides that can be present, are the following:

[0075] Anionic Tensides Such as:

[0076] Alkyl sulfates of the formula ROSO₃M, in which R represents aC₁₀-C₂₄ alkyl or hydroxy alkyl radical, preferably a C₁₂-C₂₀ alkyl orhydroxy alkyl radical, and especially preferred a C₁₂-C₁₈ alkyl orhydroxy alkyl radical, M represents a hydrogen atom or a cation asdescribed above and its ethylene oxide (EO) derivative and/or propyleneoxide (PO) derivative with an average of 0.5 to 6, preferably 0.5 to 3EO units and/or PO units;

[0077] Salts of saturated or unsaturated C₈-C₂₄ fatty acids, preferablyC₁₄-C₂₀ fatty acids, C₉-C₂₀ alkyl-benzene sulfonate, primary orsecondary C₈-C₂₂ alkyl sulfonates, alkyl glycerine sulfonates,sulfonated polycarboxylic acids as described in GB-A-1 082 179, paraffinsulfonates, N-acyl-N-alkyl taurates, alkyl phosphate esters and/oralkylether phosphate esters and/or alkylarylether phosphate esters,isethionates, alkyl succinamates, alkyl sulfo succinates, alkylglycoside sulfates, alkyl polyethoxy carboxylates; whereby the cation isan alkali metal or alkaline earth metal (sodium, potassium, lithium,magnesium), a possibly substituted ammonium radical (methyl-, dimethyl-,trimethyl-, tetramethyl-ammonium, dimethyl-piperidinium, etc.) or analkanoloamine derivative (monoethanolamine, diethanolamine,triethanolamine, etc.); Alkyl sulfonic acid esters of the formulaR-CH(SO₃M)-COOR′, whereby R signifies a C₈-C₂₀ alkyl radical, preferablya C₁₀-C₁₆ alkyl radical, R′ signifies a C₁-C₆ alkyl radical, preferablya C₁-C₃ alkyl radical and M represents an alkali metal cation (sodium,potassium, lithium), in some cases substituted ammonium (methyl-,dimethyl-, trimethyl-, tetramethyl-ammonium, dimethyl-piperidinium,etc.) or an alkanolamine derivative (monoethanolamine, diethanolamine,triethanolamine, etc.). Especially preferred are the sulfonic acidmethylesters with a radical R of C₁₄ through C₁₆;

[0078] Alkyl amide sulfates of the formula RCONHR'OSO₃M, in which the Rrepresents a C₂-C₂₂ alkyl radical, preferably a C₆-C₂₀ alkyl radical, R′represents a C₂-C₃ alkyl radical, M represents a hydrogen atom or acation as defined above and its ethylene oxide (EO) derivatives and/orpropylene oxide (PO) derivatives with an average of 0.5 to 60 EO and/orPO units;

[0079] Alkyl and dialkyl phosphates and phosphate ethers;

[0080] Non-ionic Tensides Such as

[0081] polyalkoxylated aliphatic qC₈-C₂₂ alcohols with 1 to 25 alkyleneoxide units (ethylene oxide, propylene oxide);

[0082] for example TERGITOL 15-S-9, TERGITOL 24-L-6 NMW, sold by: UnionCarbide Corp., NEODOL 45-9, NEODOL 23-65, NEODOL 45-7, NEODOL 45-4, soldby: SHELL CHEMICAL co., KYRO EOB, sold by: THE PROCTER & GAMBLE co. arecited;

[0083] glucosamide, glucamide;

[0084] the alkyl polyglycosides and their polyalkylene oxide derivativesdescribed in U.S. Pat. No. 4,565,647;

[0085] polyalkoxylated (polyethoxylated, polypropyloxylated,polybutoxylated) alkyl phenols, the alkyl substitute of which is C₆-C₁₂alkyl and which contain 5 to 25 alkylene oxide units; for example,TRITON X-45, X-114, X-100 or X-102, sold by: ROHM & HAAS co. are named;

[0086] glycerine amide derivatives of N-alkylamines (U.S. Pat. No.5,223,179 and FR-A-1 585 966);

[0087] condensation products from ethylene oxide or propylene oxide withpropylene glycol, ethylene glycol and/or glycerine, like the PLURONICseries, sold by BASF;

[0088] condensation products from ethylene oxide or propylene oxide withethylene diamin, like the TETRONIC series, sold by BASF;

[0089] Aminoxides such as C₁₀-C₁₈ alkyl dimethylamine oxides, C₈-C₂₂alkoxyethyl-dihydroxy-ethylamine oxides;

[0090] C₈-C₂₀ fatty acid amides;

[0091] ethoxylated fatty acids;

[0092] ethoxylated fatty acid amides;

[0093] ethoxylated amines;

[0094] ethoxylated amidoamines, especially those that are derived fromthe N-hydroxyethyl-N′-alkylamide-ethylene diamins;

[0095] Amphoteric and Zwitterionic Tensides Such as

[0096] Alkylbetaine, alkyl dimethyl-betaines,alkyl-amidopropyl-betaines, alkyl-amidopropyl-dimethyl-betaines,alkyl-trimethyl-sulfo-betaines, imidazoline derivatives such asalkyl-amphoacetates, alkyl-amphodiacetates, alkyl-amphodiproprionates,alkyl sultains or alkyl-amidopropyl-hydroxysultains, condensationproducts from fatty acids and protein hydrolysates, amphotericalkyl-polyamine derivatives such as AMPHOLIC XL, sold by: RHONE-POULENC,AMPHOLAC 7T/X and AMPHOLAC 7C/X, sold by: BEROL NOBEL.

[0097] These tensides are selected from a series of anionic tensidessuch as alkylsulfates and/or alkylsulfate ethers, preferably incombination with at least one amphoteric tenside such asalkylamidopropylbetains and/or alkylamphoacetates or -diacetates and, ifapplicable, in combination with at least one non-ionic tenside such asthe polyalkoxylated aliphatic alcohols and/or glucamides and/oralkylglucosides.

[0098] A tenside mixture consisting of the following is particularlypreferred for these cosmetic formulations:

[0099] approximately 5% to approximately 20%, preferably betweenapproximately 10% to approximately 15% of at least one anionic tenside,especially an alkylsulfate and/or an alkylsulfate ether;

[0100] approximately 0.1% to 15%, preferably between approximately 1% toapproximately 5% of at least one amphoteric tenside, especiallyalkylamidopropylbetain and/or alkylamphoacetate or -diacetate and

[0101] approximately 0% to 5%, preferably between approximately 1% toapproximately 3% of at least one non-ionic tenside, especially apolyalkoxylated aliphatic alcohol and/or a glucamide and/or analkylglucoside;

[0102] whereby the percentages mean percent in weight of the activetenside in the cosmetic formulations.

[0103] These clear aqueous cosmetic formulations may also contain otheradditional ingredients that are selected in such a way as not todecrease the clarity of these formulations.

[0104] These invented cosmetic formulations may also contain thefollowing:

[0105] up to 10%, preferably up to 5% polymer derivatives that have aprotective or moisturizing action on the skin or a conditioning action,such as modified celluloses (e.g., hydroxymethylcellulose,carboxymethylcellulose) or non-ionic derivatives (e.g., hydroxypropylguar meal), non-ionic derivatives (e.g., carboxymethyl guar meal) ornon-ionic/anionic derivative mixtures such as carboxyhydroxypropyl guarmeal; however, substitute or additional synthetic polymers such aspolyacrylate or synthetic cationic polymers that are known by thegeneral CTFA designation “polyquaternium,” such as the polymer MIRAPOLA15 or MIRAPOL 550 from Rhone-Poulenc or polymers that bestow dressingproperties such as vinyl pyrrolidon copolymers may be added;

[0106] up to 5% moisture retaining agents or moisturizers, especiallylike glycerine;

[0107] up to 5% calcium complexing agents like citrate ions;

[0108] up to 1% sunscreen filters such as octylmethoxycinnamate (PARSOLLCX from GIVAUDAN);

[0109] up to 0.3% bactericides such as triclosan or chlorphenesine;

[0110] up to 1% preservatives such as p-hydroxybenzoic acid methylester, -ethyl ester, and -butyl ester; sodium benzoate; or GERMABEN(trade name);

[0111] up to 0.5% thickening agents, gelling agents, or stabilizers likethe linked polyacrylates CARBOPOL sold by GOODRICH, xanthan gum,succinoglycan derivatives;

[0112] perfumes, pigments.

[0113] The material that results from the present invention isparticularly advantageous; because it can be dissolved in water, ityields solutions of greater clarity. A 1% solution (0.9% solid matter)of this pure guar meal manufactured using this new process has aviscosity of 6000 to 9000 mPa at 25° C. An aqueous solution transparencyof up to 95% can be achieved.

[0114] The viscosity was determined using a Brookfield RTV viscositymeter; the transparency of the solution by means of a photospectrometer.

[0115] The invention will be explained by means of several examplesbelow. Splits of the highest quality were used as the source materialfor the examples described.

[0116] From these examples it may be seen that treatment of theperiphery of the guar splits with a sodium hydroxide solution ofoptimized concentration in the presence of small amounts of hydrogenperoxide already leads to the elaboration of pure guar products.

[0117] These pure products demonstrate a viscosity of 5000 to 9000 mPaat a 1% concentration as well as clarity greater than 80% at a 0.5%concentration and a 1 cm light path at 500 nm, whereas conventional guarproducts in aqueous solution demonstrate light transmission of between45% to 48%.

[0118] This transparency to light can be achieved even without treatmentwith isopropanol. With isopropanol, light transparency of up to 98% isachieved because isopropanol removes phospholipids that cannot beremoved by washing with water.

[0119] After this first cleansing, the alkaline splits demonstrate awater content of 12% to 15%.

[0120] The splits are washed twice with water in a ratio of 1:7 and 1:6over a period of 6 and 8 minutes respectively.

[0121] In the process, the splits absorb water up to 70% and can theneither be ground or further modified after additional water has beenadded so that a moisture content of 76% to 78% is reached.

[0122] However, it is possible to treat the splits without the washingstep.

[0123] The ground products possess a protein content of 1.0% to 1.2% andan A.I.R percentage of approximately 0.8. Depending on the quality ofthe source material, the yield from these products is 75% to 79%.

EXAMPLE I

[0124] 370 guar splits with a galactomannane content of at least 84% aretreated for example in a preheated sigma mixer with 10% NaOH (84 ml of a33% NaOH solution) and then after one minute, additionally with 4 ml ofa 35% H₂O₂ solution that was diluted with 20 ml isopropanol. Thereaction temperature is indirectly increased by means of 90° C. hotwater to 70° C. and then kept constant.

[0125] Then a portion of the caustic solution present is neutralized by21 g of 96% H₂SO₄, diluted with 8 g of water. The mixing process iscontinued another 16 minutes at 70° C. Then, 70 g of water are quicklyadded in order to more easily remove the treated, disruptive peripheralcell layers during the mixing process. The mixing process is carried outfor 30 minutes at 70° C.

[0126] The reaction mixture is sifted through a M20 sieve, and in sodoing,

[0127] 95 g−M20 (H₂O: 16.2%) and

[0128] 360 g+M20 (H₂O: 12.9%)

[0129] Are Obtained.

[0130] The +M20 fraction displays a NaOH content 5-6% and is washedtwice with cold water, in each case using 6 parts tap water to 1 part ofthe unwashed +M20 fraction.

[0131] The washing process was carried out 5 or, respectively, 6 minuteswhile intensively stirring.

[0132] The washed, swelled splits are recovered by simple sifting.

[0133] (The alkali treatments mentioned in literature and patentliterature using 20-32% NaOH require a washing water quantity of morethan 40 parts tap water per 1 part unwashed splits.)

[0134] 916 g of swollen splits with a water content of 73.3% wererecovered after cleaning with water.

[0135] A viscosity of 7,000 mpa.s was measured at 20 rpm and 25° C.,after the homogenous solution, obtained by impact, of the swollen splitshad cooled overnight.

[0136] The 1% aqueous solution was produced in a household mixer at thehighest speed at roughly 900° C. The quantity of swelled splits to bedissolved was calculated at a water content of 10%.

[0137] A 1:1 dilution of this 1% solution yields a light transmission of81.3% up to 500 nm in a 1-cm cuvette.

[0138] N.B.

[0139] If 40% less NaOH and 40% less H₂SO₄ are used (under otherwiseidentical conditions), less abrasion (roughly 12%) and a significantlylower light transmission of roughly 75% are obtained.

EXAMPLE II

[0140] These products obtained according to Example I can besignificantly improved in their quality (viscosity, transparency) byfurther decreasing their protein and A.I.R. content. Products that arenot washed with water may be treated for 30-60 minutes with 25 percentby weight isopropanol at 65 to 70° C. without adding additional causticsolution, because the splits still contain approx. 5-6% NaOH. If washedsplits are used, the adding of 2-5% caustic solution, preferably causticsoda, is required.

[0141] Following the aqueous isopropanol treatment, the alkaline splitsare washed, brought to the necessary moisture level by adding morewater, and ground.

[0142] The transparency of the aqueous solution of such products is 93to 95%. The viscosity of a 1% aqueous solution can be set at 6,000 to7,000 mPa.s depending on reaction conditions.

[0143] The product designated as −M20 and cleaned in the above-describedmanner is a guar gum with a viscosity of 1,000 to 1,500 mPa.s at 1%concentration, which can serve as the basis for significantly improvedguar products or derivatives.

[0144] The −M20 fraction as well can also be processed for applicationsthat use alkaline oxidized guar products or derivatives. A field ofapplication would be polyester printing, for example. By using the −M20fraction, the material to be printed obtains a soft hand after thedispersion dyes used have been fixed at extremely high temperatures.

EXAMPLE III

[0145] 8,522 g of guar splits with a galactomannane content of at least84% are brought into contact, for example in an indirectly heatableDrais mixer, with 2,580 g of a 33% NaOH solution that was preheated to74° C.

[0146] After 3 minutes, 230 g of a 14% H₂O₂ solution are slowly added.

[0147] The temperature of the heterogenous reaction mixture is increasedto and maintained at 70° C. for 30 minutes.

[0148] To better control the partial neutralization with 668 g of a69.5% sulfuric acid, the reaction mixture is then cooled down to 55° C.

[0149] The reaction is continued 30 minutes at 70° C. The treated guarsplits are then washed with cold tap water for 5 minutes, using 12 partstap water for 1 part unwashed splits. In the reaction in theaforementioned mixer, practically no abrasion is produced, in such a waythat a sifting process before the washing can be dispensed with.

[0150] The washed splits have a water content of 72% and are groundfiner than M150 in the usual manner in a hot air current in aswing-hammer crusher.

[0151] The ground product still contains roughly 2% NaOH and shows aviscosity of 4,200 mPa.s at a concentration of 1%, based on 10% waterwith a 6.8 pH.

[0152] The clarity of a 0.5% solution which, was measured as described,is 82.4%.

EXAMPLE IV

[0153] 25 kg of guar splits of the same quality as used in Examples Iand II are treated for a half hour at 70° C. in a sigma mixer with 9%NaOH in the presence of 0.67 kg of a 14.1% H₂O₂ solution. A 33% solutionwas used.

[0154] The peripheral cell layers were then abraded for 15 minutes at70° C. in an open reactor 6.5 percent of weight −M20 can be removed.

[0155] The −M20 fraction was washed with tap water as described,yielding a product with a viscosity of 5,700 mPa.s (1% concentration)and a clarity (0.5%) of 81.3%.

[0156] The still adhering, treated peripheral cell layers can be abradedmechanically by an intensive rubbing of the +M20 fraction, e.g., in ahousehold coffee grinder at the lowest grinding speed.

[0157] By repeated “grinding”, roughly 12% of the peripheral cell layerscould be additionally removed, in such a way that a total of roughly18-19% of the −M20 fraction was recovered.

[0158] These peripheral cell layers can also be abraded in aqueousalcohols with intensive stirring. If, for example, 1 part of the +M20fraction is intensively stirred for 5 minutes in 1.2 parts 35 percent byweight of methyl alcohol and this process is repeated 3 times, 13.5% ofthe −M20 fraction can be recovered, in such a way that a total of 20% ofthis fraction is preserved.

EXAMPLE V

[0159] Cationic Derivatization

[0160] The product from Example III was ground and 400 g of this groundproduct was re-suspended in 1600 g of a 25 percent by weight of aqueousisopropanol solution. One hundred ml of a 30 percent by weight of NaOHsolution was added. The suspension was heated to 70° C. in a nitrogenousatmosphere for 30 minutes while constantly stirring. This reactiontemperature was maintained for 1 hour, then the suspension was cooleddown to 55° C. The stirring was interrupted and after the reactionproduct was precipitated, the excess was poured off.

[0161] The reaction product was washed with 1,000 ml of a 50 percent byweight isopropanol solution and then treated with 10 ml of glacialacetic acid in order to neutralize a stoichiometric quantity of NaOH.

[0162] The excess was poured off after the reaction product wasprecipitated. 7.8 g NaOH was removed in this way.

[0163] 225 g of a 40 percent by weight 2,3-epoxypropyl trimethylammonium chloride solution was added and left to penetrate into thealkaline-treated product for 1 hour at 30° C. Afterward, 1,100 ml of an85 percent by weight isopropanol solution was used as suspension medium.The nitrogen atmosphere was reestablished and the suspension was heatedto 65° C. This temperature was kept constant for 40 minutes.

[0164] The reaction product thus comes into contact with atmosphericoxygen so that the final viscosity of the cationic guar product could becontrolled.

[0165] The reaction was carried out 45 minutes at 65° C. The product wasthen washed with 800 ml of a 85 percent by weight of isopropanolsolution and then with 1,000 ml of the same solution. During the washingprocess, 25 ml of 99 percent by weight glacial acetic acid was added,whereby the caustic solution was neutralized.

[0166] The product was recovered by filtration and dried with hot air at70° C.

[0167] This cationic guar displayed a 880 mPa.s viscosity (based on 10%moisture) at 1% concentration in water and a light transmission(clarity) of 94.2%.

EXAMPLE VI

[0168] Carboxymethylation

[0169] 350g of a +M20 fraction with a moisture level of 7.5% wasmoistened with 100 ml of cold water. After 15 minutes, the majority ofthe monochloroacetate-Na solution consisting of 79 g ofmonochloroacetate-Na and 184 g water was slowly added while stir ringfor 24 minutes. The remaining 100 ml of this solution was quickly addedfor 5 minutes. The adding of the reagents took place at roomtemperature.

[0170] After 16 more minutes of incubation while stirring, thetemperature was increased to 50° C. Then, 27 g of NaOH pellets wasadded. Due to the exothermic reaction of the NaOH pellets used, thetemperature quickly increased to 65-66° C. and was maintained there for36 minutes.

[0171] The reaction product was removed from the reactor and washedtwice with water in a ratio of 1:6. Due to the very rapid waterabsorption of the cleaned carboxymethyl splits not treated with borax,their dwell time in water was limited to 2 minutes in each case. Theweight of the highly swelled splits was 2,640 g. A dehydration step withisopropanol (1,500 g was used) was therefore necessary.

[0172] 3,261 g of the filtrate was recovered. The weight of thealcohol-moistened, carboxymethylated splits was 879 g with a volatility66.8%.

[0173] Since no precautions were taken by means of an inert nitrogendome during the reaction, the splits were in contact with air throughoutthe reaction, which caused a considerable depolymerization.

[0174] The viscosity of a 1% solution of the carboxylated splits was1,720 mPa.s with a clarity of 92.7%. These values were obtained at atemperature 25° C.

EXAMPLE VII

[0175] Four hundred grams of the preferred guar split quality with agalactomannane content of at least 84% was first diluted in a preheatedsigma mixer with 4 ml of 35% H₂O₂, treated for 9 minutes with 21 ml ofdemineralized water, after which 40 g of NaOH dissolved in 61 ml ofdemineralized water was added hot.

[0176] Within 3 minutes, the reaction mixture attained the desiredtemperature of 68° C. The reaction temperature of 68°-72° C. wasmaintained for 20 minutes. Most of the water was then drawn off from thereaction mixture by ventilation and indirect heating for 23 minutes.

[0177] The reaction mixture was sifted through M20, thus obtaining 30 gof −M20 and 437 g of +M20 (10.1% H₂O content). The +M20 fraction waswashed twice with water, in each case using 6 parts tap water to 1 partof the unwashed +M20 fraction. The respective washing times were 4 and 5minutes.

[0178] The washed, swollen splits were recovered by simple sifting; 892g of swollen splits were obtained that had a water content of 67.8%.These splits were placed in solution in typical manner and this solutionproduced a viscosity of 2,300 mPa.s and a light transmission of 86.4%(measured according to the description in Example I).

[0179]FIG. 1: The flow chart shows the treatment, according to theinvention, of the splits with caustic solution and hydrogen peroxide andthe further processing possibilities following the alkaline treatment.

EXAMPLE VIII

[0180] Clear Conditioning Shampoo

[0181] A clear conditioning shampoo with the following composition isproduced according to the method known by the experts:

[0182] Components g (of active ingredient)/100 g

[0183] Sodium lauretyhl-2-sulfate 7.5 (aqueous solution of sulfatizedethoxylated lauryl alcohol with 28% active ingredient)

[0184] Cocoamidopropyl betaine (aqueous 2.5 solution with 25% activeingredient)

[0185] Hydroxypropyl trimethyl ammonium 0.3 chloride guar gum fromExample 5 (100% active ingredient)

[0186] Water ad 100

[0187] This formulation is set at a viscosity of 3,000 mPa.s by addingsodium chloride.

[0188] The transparency measured for 600 nm is 97%.

EXAMPLE IX

[0189] Clear Shower Gel

[0190] A clear shower gel with the following composition is producedaccording to the method known by the experts (adding of themicro-emulsion of amino-modified silicon to the rest of the mixture):

[0191] Components g (of Active Ingredient)/100 g

[0192] Sodium lauretyhl-2-sulfate 8 (aqueous solution of sulfatizedethoxylated lauryl alcohol with 28% active ingredient)

[0193] Cocoamidopropyl betaine (aqueous 4 solution with 25% activeingredient)

[0194] Hydroxypropyl trimethyl ammonium 0.2 chloride guar gum fromExample 5 (100% active ingredient)

[0195] MIRASIL ADME (RHODIA CHEMICALS) 0.3 (aqueous amodimeticonemicro-emulsion with 30% active ingredient and a particle size of 25 nm)

[0196] Water ad 100

[0197] This formulation is set at a viscosity of 2,500 mPa.s by addingsodium chloride.

[0198] The transparency measured for 600 nm is 96%.

1. A process for the production of pure guar meal, wherein the followingsteps are involved: (a) treatment of the guar split with an alkalinesolution in the presence of hydrogen peroxide at 65 to 70° C.; (b)partial neutralization of the alkaline split with an organic orinorganic acid; (c) mechanical removal of the peripheral cells layers ofthe guar split; (d) treatment of the split with an aqueous alcoholsolution; and (e) grinding of the split into meal.
 2. A processaccording to claim 1, wherein the alkaline solution employed in step (a)is caustic soda, preferably in a concentration of 25 to 50% by weight,most preferably in a concentration of 33% by weight, and in a quantityof 6-10%, as based on the starting material.
 3. A process according toclaim 1 or 2, wherein the quantity of hydrogen peroxide used in step (a)is 0.175 to 0.35% by weight, most preferably 0.175% by weight, and ahydrogen peroxide solution of 35% by weight is employed.
 4. A processaccording to one of the preceding claims, wherein the acid in step (b)is sulfuric acid, phosphoric acid, or another suitable organic acid,preferably acetic acid.
 5. A process according to claim 4, wherein thesulfuric acid used in step (b) is employed in a concentration of 60 to80% by weight, preferably 70% by weight.
 6. A process according to claim4, wherein the phosphoric acid used in step (b) is employed in aconcentration of 60 to 85% by weight, preferably 75% by weight.
 7. Aprocess according to one of the preceding claims, wherein the alcoholsolution employed in step (d) is an aqueous solution of ethanol,methanol, or, preferably, isopropanol.
 8. A process according to one ofthe preceding claims, wherein the aqueous alcohol solution is preferablya 20 to 40% by weight isopropanol solution, most preferably 25% byweight.
 9. A process according to claim 7 or 8, wherein the splits,after removal of the peripheral cell layers in step (c) and beforetreatment with an aqueous isopropanol solution in the presence of a lye,preferably caustic soda, at 60 to 70° C., in step (d) are washed twicewith water.
 10. Pure guar meal according to one of the preceding claims,wherein said guar meal is subjected to a derivatization by means ofcarboxy methylation, hydroxy propylation, or cationization, orcombinations thereof.
 11. Guar meal which, as a 1% aqueous solution, hasa viscosity of up to 9000 mPa s and a content of proteins and materialsthat cannot be hydrolized by acid of 0.8 to 1.2% and which, as a 0.5%aqueous solution, exhibits a transparency of at least 80% measured at awavelength of 500 nm, produced with the process according to one of thepreceding claims.
 12. Guar meal according to claim 10, wherein thetransparency of a 0.5% solution of these derivatives measured at awavelength of 500 nm extends up to 98%.
 13. Guar meal according to oneof claims 10, 11, and 12, for use as a thickening agent for foodstuffs,cosmetics, pharmaceutical products, for pigments and lacquers, fortextile pigments, for crude oil extraction, and for explosivesubstances.
 14. Hydroxypropyltrimethyl ammonium chloride guar meal, thatis obtained by etherizing guar meal obtained with the process accordingto one of claims 1 to 9 with 2,3 epoxypropyltrimethyl ammonium chlorideas a cationic etherizing agent, under basic conditions and in an inertgas atmosphere, followed by purification and separation. 15.Hydroxypropyltrimethyl ammonium chloride guar meal according to claim14, wherein etherization is performed in two primary steps: an initialstep, in which the cationic etherizing agent is diffused in the guarflower, under alkaline conditions and in an inert gas atmosphere at atemperature from 20 to 55° C., preferably 30 to 50° C., and is thensuspended in an aqueous alcohol solution, particularly awater-isopropanol solution containing 25 to 70% by weight isopropanol,and a second step, in which the actual etherization is performed in aninert gas atmosphere at a temperature of 50 to 70° C., most preferablyat a temperature of 60 to 65° C.
 16. The use of a hydroxypropyltrimethylammonium chloride guar meal according to claim 14 or 15 in clear,aqueous cosmetic formulations which are intended for application on thehair and/or skin and are to be rinsed away, as a conditioner and/or as adepositing agent for further conditioning agents in diluting thecosmetic formulation.
 17. Use according to claim 16, wherein thesecosmetic formulations contain 0.05 to 0.5%, preferably 0.1 to 0.3%hydroxypropyltrimethyl ammonium chloride guar meal and at least 60% byweight water and exhibit a permeability of at least 92% measured at 600nanometers.
 18. Use according to claim 16 or 17, wherein these clearcosmetic formulations also contain a non-volatile silicon in the form ofparticles with a diameters of less than 35 nanometers, preferably 20 to25 nanometers.
 19. Use according to claim 18, wherein the silicon ispresent in a quantity of 0.1 to 1% by weight, preferably 0.5 to 1% byweight, expressed as active ingredient, relative to the weight of thecosmetic formulations.
 20. Clear, aqueous cosmetic formulations whichare intended for use on the hair and/or skin and are to be rinsed awayand which contain the following ingredients, relative to their weight 8to 30% by weight, preferably 10 to 20% by weight, at least, of anon-ionic, anionic, amphoteric, or dipolar surfactant, expressed asactive ingredient, 0.05 to 0.5% by weight, preferably 0.1 to 0.3% byweight, hydroxypropyltrimethyl ammonium chloride guar meal according toclaim 14 or 15, when so required, 0.1 to 1% by weight, preferably 0.5 to1% by weight, at least, of a non-volatile silicon in an aqueousemulsion, whose particle size is less than 35 nanometers, preferablyabout 20 to about 25 nanometers, expressed as active ingredient, and atleast 60% by weight water, preferably at least 75% by weight.
 21. Useaccording to one of claims 16 to 19, or of cosmetic formulationsaccording to claim 20, wherein the hydroxypropyltrimethyl ammoniumchloride guar meal exhibits a substitution degree of about 0.01 to about0.4, preferably 0.05 to 0.25, and a molecular weight of 50,000 to 3·10⁶.22. Use according to one of claims 16 to 19, as well as 20, or ofcosmetic formulations according to claim 20 or 21, wherein these clear,aqueous formulations exhibit a permeability of at least 92% measured at600 nanometers.
 23. Use according to one of claims 16 to 19, or 22, orof cosmetic formulations according to one of claims 20 to 22, whereinthese clear cosmetic formulations are present in the form of aconditioning shampoo, a shower gel, or a liquid soap.